1、August 7, 20011SUBJECT 1807OUTLINE OF INVESTIGATIONFORFIRE-RESISTANT CABLE COATING MATERIALSIssue Number: 3August 7, 2001COPYRIGHT 1989, 2001 UNDERWRITERS LABORATORIES INC.AUGUST 7, 2001SUBJECT 18072No Text on This PageCONTENTSFOREWORD 4METHOD1 Scope .52 General 53 Summary of Method .54 Environmenta
2、l Conditioning 5APPENDIX A SUPPLEMENTARY TESTS AND DATAA1 General .A1A2 Samples A1A3 Ampacity Reduction Testing .A1AUGUST 7, 2001 SUBJECT 1807 3FOREWORDA. This Outline of Investigation contains basic requirements for products covered by UnderwritersLaboratories Inc. (UL) under its Follow-Up Service
3、for this category within the limitations given below andin the Scope section of this Outline of Investigation. They are subject to revision as further experience andinvestigation may show is necessary or desirable.B. The observance of these requirements by a manufacturer is one of the conditions of
4、the continuedcoverage of the manufacturers product.C. A product which complies with the text of this Outline of Investigation will not necessarily be judged tocomply with the Outline of Investigation if, when examined and tested, it is found to have other featureswhich impair the level of safety con
5、templated by these requirements.D. A product that contains features, characteristics, components, materials, or systems new or differentfrom those covered by the requirements in this Outline of Investigation, and that involves a risk of fire orof electric shock or injury to persons shall be evaluate
6、d using appropriate additional component andend-product requirements to maintain the level of safety as originally anticipated by the intent of thisOutline of Investigation. A product whose features, characteristics, components, materials, or systemsconflict with specific requirements or provisions
7、of this Outline of Investigation does not comply with thisOutline of Investigation. Revision of requirements shall be proposed and adopted in conformance with themethods employed for development, revision, and implementation of this Outline of Investigation.E. UL, in performing its functions in acco
8、rdance with its objectives, does not assume or undertake todischarge any responsibility of the manufacturer or any other party. The opinions and findings of ULrepresent its professional judgement given with due consideration to the necessary limitations of practicaloperation and state of the art at
9、the time the Outline of Investigation is processed. UL shall not beresponsible to anyone for the use of or reliance upon this Outline of Investigation by anyone. UL shall notincur any obligation or liability for damages, including consequential damages, arising out of or inconnection with the use, i
10、nterpretation of, or reliance upon this Outline of Investigation.F. Many tests required by the Outline of Investigations of UL are inherently hazardous and adequatesafeguards for personnel and property shall be employed in conducting such tests.AUGUST 7, 2001SUBJECT 18074METHOD1 Scope1.1 This is a t
11、est method for determining the effect of flame-retardant cable coating materials.1.2 The purpose of this test method is to determine whether the flame propagation characteristics ofnonconforming cables is enhanced to the degree that the coated cables meet vertical flame testrequirements. The reducti
12、on in the cables ampacity rating due to the application of a coating may also beinvestigated.1.3 This test method does not cover the construction requirements for any cable or electrical, optical, andother performance requirements.2 General2.1 Values stated without parentheses are the requirement. V
13、alues in parentheses are explanatory orapproximate information.3 Summary of Method3.1 Cable coating materials are investigated by conducting a flame test on the coating as applied togrouped cables in a tray. The cables that serve as the substrate for this test do not meet the vertical flametest requ
14、irements (maximum damage height) described in the Reference Standard for Electrical Wires,Cables, and Flexible Cords, UL 1581. The method of testing coating materials is essentially equivalent tothe method described in the document, except that three full layers of cables are used rather than aparti
15、al, single layer, and that two ignition burners (applied to both the front and rear of the vertical cabletray assembly) are used instead of a single burner. Three modified UL 1581 tests are conducted on thecoating material to be Classified.4 Environmental Conditioning4.1 PURPOSE When the material be
16、ing investigated is a mastic type coating or when the coating isintended for outdoor use, the permanence of the flame-retardant properties is to be investigated bysubjecting coated samples to specific conditioning environments for specified periods of time, thensubjecting the samples to a radiant he
17、at source with the rate of heat release measured and recorded. Therate of heat release measurements obtained from the conditioned samples are then compared to the rateof heat release measurements for unconditioned samples. See Tables 4.1 and 4.2 for cable constructionand test preparation information
18、. The conditioning environments are chosen based upon the chemicalcomposition of the coating. The exposure may include but is not limited to:a) Aging The samples are placed in a circulating air-oven which is maintained at 70C.Samples are removed at four intervals covering a nine month period.b) High
19、 Humidity The samples are exposed to an environment of 97 100 percent controlledhumidity and 95F for a period of six months.c) Industrial Atmosphere (CO2-SO2Air Mixture) The samples are exposed to an amount ofsulphur dioxide equivalent to 1 percent of the volume of the test chamber. An equal volume
20、ofcarbon dioxide is also present. A small amount of water is maintained at the bottom of thechamber and the chamber is maintained at 95F. The exposure period is one month.AUGUST 7, 2001 SUBJECT 1807 5d) Wet, Freeze and Dry Cycle The samples are exposed alternately to water (0.7 in./h for 72hours), m
21、inus 40F (for 24 hours) and dry atmosphere (120F for 72 hours) for a period of 12weeks.e) Weatherometer The samples are exposed to ultraviolet light and water while mountedvertically on the inside of a cylinder 31 inches in diameter and 18 inches in height. Two 1/2 inchdiameter carbon electrodes are
22、 located in the center of the cylinder. The cylinder revolves at 1rpm exposing the sample in turn to water spray nozzles. During each 20 min. period, thesamples are exposed to light and water spray for 3 minutes and to light for only for 17 minutes.The duration of the exposure is 720 hours.f) Salt S
23、pray Samples are exposed to a salt spray for 90 days per ASTM Method B117-64.Table 4.1Cable constructionsConductors Insulation Insulation covering cable jacket cableCablereference NumberSize,AWG MaterialThickness,MaterialThickness,MaterialThickness, Diameter,inch inch inch inchA 7 12 Polyethylene 0.
24、021 Polyvinylchloride0.007 Polyvinylchloride0.061 0.60B 9 12 Cross-linkedPolyethylene0.042 None Cross-linkedPolyethylene0.051 0.75C 7 12 Cross-linkedPolyethylene0.041 None Cross-linkedPolyethylene0.074 0.60D 7 12 Polyvinylchloride0.028 Nylon 0.006 Polyvinylchloride0.054 0.50NOTES1 All conductors are
25、 stranded copper.2 All thicknesses are approximate.3 Identification of materials was based upon manufacturers product specifications.Table 4.2Number of cable length used for 6-by-6 inch sampleCable type Number of lengthsA9B8C10D12AUGUST 7, 2001SUBJECT 18076APPENDIX A SUPPLEMENTARY TESTS AND DATAA1 G
26、eneralA1.1 The test program discussed in the previous sections may be expanded to include the developmentof additional information intended to be used by local authorities having jurisdiction. This informationconcerns the operating of cable ampacity rating due to the application of a coating.A2 Samp
27、lesA2.1 The samples used in the tests described below shall be fabricated under the observation of arepresentative of Underwriters Laboratories Inc.A3 Ampacity Reduction TestingA3.1 PURPOSE The reduction in the current capacity (ampacity) due to the application of a coating isdetermined in accordanc
28、e with the Outline of Investigation for Tests for Ampacity of Insulated ElectricalConductors Installed in Fire Protective Systems, Subject 1712.A3.2 The test consists of assembling a minimum 72-inch long sample comprised of grouped tray cablesin a cable tray. The electrical current required to attai
29、n the rated temperature of the cables (as determinedby thermocouples affixed to the metal conductors of the cable) is measured and recorded for variousambient temperatures in free air. The cable coating material is then applied to the cables.A3.3 After curing, the tests are repeated.A3.4 To provide
30、information on different cable sizes, three different sizes shall be investigated:a) 1 conductor (250 MCM),b) 3 conductor (8 AWG), andc) 3 conductor (16 AWG).The ampacity reduction of each coated tray cable at each ambient temperature is calculated as follows:AUGUST 7, 2001 SUBJECT 1807 A1in which:Iiis the current (amperes) required to attain rated temperature of tray cable in free air andIfis the current (amperes) required to attain rated temperature of coated tray cable.AUGUST 7, 2001SUBJECT 1807A2
